Computational and Mathematical Methods in Medicine
Volume 2013 (2013), Article ID 507143, 6 pages
Research Article

Concentration-Invariant Odor Representation in the Olfactory System by Presynaptic Inhibition

1School of Automation Science and Engineering, South China University of Technology, Guangzhou 510641, China
2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China

Received 24 December 2012; Accepted 30 January 2013

Academic Editor: Jian Yang

Copyright © 2013 Danke Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The present study investigates a network model for implementing concentration-invariant representation for odors in the olfactory system. The network consists of olfactory receptor neurons, projection neurons, and inhibitory local neurons. Receptor neurons send excitatory inputs to projection neurons, which are modulated by the inhibitory inputs from local neurons. The modulation occurs at the presynaptic site from a receptor neuron to a projection one, leading to the operation of divisive normalization. The responses of local interneurons are determined by the total activities of olfactory receptor neurons. We find that with a proper parameter condition, the responses of projection neurons become effectively independent of the odor concentration. Simulation results confirm our theoretical analysis.